This invention relates to a movable support which in very general terms can be said to be similar to a castor.
A trailing castor provides wheeled support for an object which may be moved in different directions with the disposition of the axis, about which the castor wheel rotates, changing as required It is necessary though for movement of the object actually to take place before the orientation of a castor is altered. In certain applications this lag, or dead space, is not acceptable.
It is also known to make use of a sphere which projects from, and which is held captive partially within, a cylinder. This type of arrangement permits immediate movement of the support in any direction, for all practical purposes eliminating any lag, but due to the close fit between the sphere and its support within the cylinder the operation of the device can be affected by grit which may become lodged between the surface of the sphere and an opposing surface of the sphere support.